Pressure filter



July 3, 1945. w. o. DAMME ET AL PRESSURE FILTER Filed April 8, 1940within a casing.

cleaning.

prises a pressure housing I,

Patented July 3, 1945 v UNITED STATE PRESSURE FILTER Walter City, biomm,

tion of Missouri Damine and Raymond assignors to Butler Manufac- KansasCity, Mo., a corpora- J. Gabler,

Application April 8, 1940, Serial No. 328,446

our invention relates to pressure filters'and more particularlyto apressure filter including in combination a novel means enabling therapid, expeditious and convenient cleaning eithe same. In pressurefilters employed for filtering dry I cleaning solvents, a filter aid isemployed, adapted to coat the outside of filter screens positionedPeriodically, it becomes necessary to clean the filter to remove muck,sludge, and contaminated filter cake. Heretofore, it has been thepractice to drain the solvent from the filter. Considerable solvent isadsorbed by the muck and used filter cake and, it this is removed beforeit is substantially dry, a distinct fire hazard is presented.Furthermore, the solvent cons! (01. zit-181) vided with a door ll,pivoted around hinges II and secured in place by stud bolts I2. A drainpipe l3 terminates in a chamber M. The chamher I 4 ispro'vided with aremovable bottom II.

tom I]. fA-filter cloth I wire mesh basket It, as can readily be seen bytained in the sludge represents a loser solvent.

A considerable time period is involved in draining the solvent from thesludge and the cleaning of a filter has heretofore been atime-consuming, risky, and laborious task.

One object of our invention is to provide a novel filter provided withmeans for rapidly, expeditiously and safely cleaning the same.

Another object of our invention is to provide a pressure filter in whichthe maximum amount of solvent is recovered irom the muck bed beforeOther and further objects or our invention will appear from thefollowing description.

In the accompanying drawing which forms part of the instantspecification and are to be read in conjunction therewith and in whichlike reierence numerals are used the various views;

Figure 1 is'an elevation of a pressure filter with parts broken away,made in accordance with an embodiment oi our invention.

Figure 2 is a fragmentary sectional view of the bottom of our filter.

Figure 3 is a sectional view taken along the line 3-301! Figure 2.

Referring now to the drawing, the filter cominto which the liquid to befiltered is introduced through pipe 2 by means of a pump (not shown). Aplurality of filter screens 3 are removably seated in a manifold 4, fromwhich the filtered liquid is withdrawn. The top of the housing is closedby a cover I, held in closed position by means of pivoted dogs 5,provided with pressure .nuts 1 adapted to be screwed upon the threadeddogs. The cover is carried by a pivoted arm 8. Themter is provided withfilter scraping means known to the art, operated by a handle 9. Thelower to indicate like parts in a basket It of wire mesh is providedwith a botsack II is supported by the referenceto Figure 2. The drainedliquid isfiltered by the filter comprising the wire mesh basket l iandla filter cloth sack ll, andpasses out through drain pipe I!controlled by valve 2|. A pipe 2| communicates with the interior or thepressure filter; A check valve 22 is positioned outboard of the. pipe2|. A reducing valve 23 communicates with the check valve 22 and a stopvalve 24 controls compressed air from pipe 25.

'In operation, when it is desiredto clean the filter, the valve 2!isopened, and valve 24 is opened. Compressed air from a suitable sourcepasses through the reducing valve 23 and. isreten pounds per squareinch. The superimposed pressure on top of the unfiltered solvent withinthe housing forces it outwardly through the auxiliary filter in chamberM and thence through drain pipe 18. The drained solvent, which in theprior art had to -be thrown away since it contained contaminated ienceand without filter powder and muck in suspension, is thus re. coveredandmaybe passedtothebodyofthedry with shovels and disposed of withoutinconvenpercentase or solvent ter aid and cannot be time will berequired to drain the filter.

, portion of the filter. below the manifold 4 is pm as muck as has beenthe case heretofore.

It will be observed that we employ a controlled air pressure. This isvery important and Varies with the particular filter aid employed. Itthe air pressure is too high, channels will be formed in the muck bedand the solvent cannot be removed as the air will blow through thechannels thus formed. It the pressure is too low, a longer The longertime is not serious but the upper limit of air pressure should be suchthat no channeling will occur.

It will be seen that we have accomplished the objects 0! 0m invention.We have provided a pressure filter which may be readily andexpeditiously drained, and the muck bed removed} with minimuminconvenience and fire danger, as well pipe. The basket type auxiliaryfilter may be quickly removed and cleaned.

It will be understood that certain features and sub-combinations are ofutility and may be employed without reference to other features andsub-combinations. This is contemplated by and is within the scope of ourclaims. It is further obvious that various changes may be made indetails within the scope of our claims without departing from the spiritof our invention. It is,

not to be limited to the specific details shown and described.

Having thus described our invention, we claim: 1. A pressure filterincluding in combination a housing meansxfor introducing liquid intosaid housing, filter leaves within said housing, a manifold forsupporting said filter leaves means for withdrawing filtered liquid fromsaid manifold, said housing being formed with an opening below saidmanifold, a door normally closing said opening, a drain opening formedin said housing adjacent the bottom thereof, a chamber communicatingwith said opening, an auxiliary filter within said chamber, saidauxiliary filter comprising a wire screen basket and a sack of filtercloth supported by said basket, a drain pipe communicating with saidchamber for the removal of liquid filtered by said auxiliary filter fromsaid chamber, means for admitting air under pressure into the filterhousing above the muck bed deposited therein by the said liquid, and apressure control means for maintaining the air under sufllcient pressureto express liquid adsorbed in the bed without channeling or otherwiseagitating the said bed whereby to leave the bed in a substantially drycondition. 3

2. A pressure filter including in combination a housing means forintroducing liquid into said I therefore, to be understood that ourinvention is housing, filter leaves within said housing, a manifold forsupporting said filter leaves means for withdrawing filtered liquid fromsaid manifold,

said housing being formed with an opening below said manifold, a doornormally closing said open-,

ing, a drain opening formed in said housing adiacent the bottom thereof,a chamber communieating with said opening, said chamber being. formedwith a separable bottom, means for removablysecuring said bottom inchamber closing position, an auxiliary filter within said chamber,

a drain pipe communicating with said chamber for the removal of liquidfiltered by said auxiliary to leave the bed in a substantially drycondition.

3. A pressure filter including in combination a housing means forintroducing liquid into said housing, filter leaves-within said housing,a manifold for'supporting said filter leaves means for withdrawingfiltered liquid from said manii 1d, said housing being formed with anopening bel w said manifold, a door normally closing said opening, adrain opening formed lnsaid housing adjacent the bottom thereof, achamber communicating with said opening, said chamber being formed witha separable bottom, means for removably securing said bottom in chamberclosing position, an auxiliary filter within said chamber, saidauxiliary filter comprising a wire screen basket and a sack of filtercloth supported by said basket, a drain pipe communicating with saidchamber for the removal of liquid filtered by said auxiliary filter fromsaid chamber, means for admitting air-under pressure into the filterhousing above the muck bed deposited therein by. the said liquid, and apressure control means for maintaining the air under suificient pressureto express liquid adsorbed in the bed without channeling or'oth'erwiseagitating the said bed whereby to leave the bed in a substantially drycondition.

. RAYMOND J. GABLER.

WALTER O. DAMME.

